Warming up the engine: the coolant temperature sensor transmits information about the increasing heating of the coolant to the control unit. The control unit issues a command to close the idle speed stabilization valve, and the injection duration returns to the standard level.
Idling: based on the information received from the throttle potentiometer and the fresh air flow meter, the control unit knows when the engine is idling. If the speed drops, the control unit changes the ignition timing; at the same time, the throttle control unit increases the air flow, resulting in a slightly increased amount of fuel injected.
Standard operation does not require any special equipment. The position of the throttle valve and the amount of air passing through its meter determine the duration of the injection valves opening.
Accelerations: rapid opening of the throttle valve is recognized by the control unit as acceleration based on the signal received from the throttle valve potentiometer.
Adjustment via lambda probe: for the catalytic converter to function properly, it is necessary to constantly change the slightly enriched and slightly lean fuel-air mixture. Information on the residual oxygen content in the exhaust at the moment lambda probe (in a catalytic converter) transmits it to the control unit, which in a split second gives the order to the injectors to lengthen or shorten the injection time and, consequently, the supply of gasoline.
Traction cut-off: information that the foot has been removed from the gas pedal is again sent to the control unit via the throttle potentiometer in the throttle control unit. If, at the same time, the coolant temperature sensor signals that the engine has reached its operational warm-up, and the Hall sensor in the distributor sends information that the engine speed has exceeded 1500 rpm, the control unit no longer commands the injectors to open.
Full load: at full load with the accelerator pedal fully depressed, the engine requires an increased amount of fuel. Based on the "full throttle" signal received from the throttle potentiometer in combination with the corresponding signal from the fresh air flow meter, the control unit recognizes the "full throttle" condition and forces the injectors to inject longer.
Speed limit: the control unit switches off the injectors to protect the engine from overspeeding if it exceeds 6500 rpm (1.6L engine) or 6800 rpm (1.8L engine).
Emergency run function: if one of the sensors does not provide information or provides meaningless information, Motronic does not yet fail. The control unit selects the so-called auxiliary value, which is in the database.